Biogeochemical Selectiveness of Cedars Over Metamorphic Rocks of the Escambray Complex, Sancti Spíritus, Cuba/Abstract

Abstract

Cedars, growing over well developed alluvium overlying Cretaceous metamorphic rocks of the Escambray Complex in Central Cuba, were sampled to determinate whether concentrations of copper and other pathfinder elements in plant tissue were related to the ore in the studied sector. These results are compared to those obtained from a soil sampling using the same grid as for the biogeochemical sampling. At each sampling point, leaves, flowers, and the end of young branches were sampled. The main elements concentrated on cedars are lead (64,7%), silver (23,6 %), and copper (23,5%), which are elements directly related to the studied pyrite-copper outcrop. Soil samples chiefly concentrate molybdenum (81%), which is not a pathfinder element for this type of ore. Accordingly to the results of the degree of contrast of the different anomalies, the best materials to be sampled are the ends of young branches. However, also the flowers and the leaves from cedar give better result than the soil sampling. A compound sample of branches, flowers and leaves is also recommended for sampling. Since the biogeochemical sampling is more effective, and it reduces the overall quantity of samples, it is recommended to introduce this method, although more experimental work should be done to improve the quality of the interpretation. These results are also a demonstration of the effectiveness of biogeochemical samplings in tropical countries.